PROJECT SUMMARY Human attentional capacity is severely limited. Visual performance is enhanced in familiar environments because long-term memory (LTM) can be used to guide visual attention to the most relevant information in the environment. Humans repeatedly encounter familiar environments, and LTM-guided attention allows for more efficient use of cognitive resources. While this process has proved to be a key part of healthy cognitive function, supported by the parietal cortex, cerebellum, striatum, and thalamus in adults, almost nothing is known about how LTM-guided attention develops in children. Furthermore, we know very little about how variation in the environment can affect development of LTM-guided attention. Poverty is associated with delays in cognitive development and impairments in academic performance. The proposed studies aim to provide deeper understanding of the environmental factors that contribute to this disruption in development with a specific interest in LTM-guided attention as a possible underlying mechanism of disparities in cognitive development among children raised in low SES environments. Study 1 of this proposal aims to characterize the developmental pattern of LTM-guided attention in children from a range of SES backgrounds (Aim 1). Study 2 will examine the relationship between lack of cognitive stimulation and environmental complexity, often associated with low SES environments, and development of LTM-guided attention using well-established observational methods of the home environment and of school quality (Aim 2). Study 3 will investigate age- related neural changes in the brain network that supports LTM-guided attention and neural differences related to SES and environmental complexity (Aim 3). The sample for the Study 1 will include 120 typically developing children ages 5-16 years from a range of SES backgrounds. The sample for Study 2 will include 120 children aged 5-6 years, a period of rapid development in attentional control, recruited to ensure substantial variation in family income. Study 2 will involve intensive observation of the home environment, parent interviews, and child cognitive tasks. Study 3 will involve a longitudinal follow-up of participants in Study 1 to undergo structural and functional MRI scanning to gain understanding of the structural and functional associations with LTM-guided attention across development and different SES levels. The results of these studies will provide insight into the cognitive and neural development of LTM-guided attention, a key component of healthy cognitive function. Furthermore, it will contribute to the field's understanding of the factors associated with atypical cognitive and neural development in children raised in poverty. This award will provide the candidate, who has a strong background in cognitive neuroscience in adults, with training in developmental methods and developmental cognitive neuroscience to facilitate her transition to an independent research career.